Reconstitution means for safety device

ABSTRACT

The present disclosure describes a needle guard device or system that can be used with drugs requiring reconstitution. The needle guard is preferably a passive needle guard that can be used during reconstitution without activating the safety mechanism. Following administration of the medication, the needle guard shields a user from inadvertent needle sticks by extending a protective shield over the needle.

CROSS-RELATIONSHIP TO PENDING APPLICATIONS

This application is a divisional of application Ser. No. 12/368,604filed Feb. 10, 2009, which claims priority to provisional applicationSer. No. 61/027,742 filed Feb. 11, 2008, which are incorporated hereinby reference.

FIELD

This invention relates generally to syringe systems and methods formixing and delivering a therapeutic agent formed by combining a diluentwith a lyophilized drug or a concentrated drug. More specifically, thisinvention relates to syringe systems, including a passive needle guard,used for reconstitution of lyophilized or concentrated drugs and methodsfor using such systems.

BACKGROUND

Lyophilization is a process by which the volatile components of a drugare removed in order to extend the shelf-life of the medication.Lyophilization may involve the rapid freezing of a material at a verylow temperature followed by rapid dehydration. Solvents such as waterare removed from the drug yielding a substance that is more stable andcan be stored. Lyophilized drugs are generally stored in a glass vial orcartridge and covered by a rubber stopper or septum.

In order to administer the lyophilized drugs, the drug must generally bereconstituted. Reconstitution is the process of hydrating drugs that arepackaged and stored in a dry lyophilized state. A diluent, such aswater, saline, 5% Aqueous Dextrose or the like, is added to thelyophilized drug and the combination is mixed until the drug is fullydissolved. A syringe is typically used to inject the diluent into thevial containing the lyophilized drug. The syringe may be pre-filled withthe diluent or the user may first withdraw the diluent from a secondvial or container into the syringe. After the diluent is added to thevial containing the lyophilized drugs, the contents are then mixed toform a therapeutic agent.

After complete mixing of the diluent and the lyophilized drug, thetherapeutic agent may be aspirated back into the syringe. Once thetherapeutic agent is in the syringe, the medication is administered tothe patient. Usually the therapeutic agent is administered within ashort time after reconstitution in order to ensure that the drug is notdegraded by the solvent.

Most current systems for reconstitution expose the user to the risk ofinadvertent needle sticks. In addition, current systems may notadequately prevent the possible reuse of the syringe. A number of needleguards for syringes have been developed that are intended to preventaccidental needle sticks and/or inadvertent reuse of a syringe. However,because syringe safety shield devices normally actuate when the plungeris fully advanced during the administration of the drug, these samedevices will prematurely actuate the safety shield during the drugreconstitution phase as the diluent is added to the lyophilized drug.Therefore, a method for preventing the activation of the safety shieldduring drug reconstitution is highly desirable.

Accordingly, a syringe system that can be used for reconstitution andthat would automatically activate a needle shield during or followingadministration of the therapeutic agent would be considered useful.

SUMMARY

The present invention is directed to a syringe system for reconstitutionof lyophilized or concentrated drugs. The present invention is alsodirected to the combination of such a system with a passive needle guardthat is automatically activated to extend a shield to cover a needle ofthe syringe and to methods of making and using such systems. Typically,a passive needle guard shield is activated when a radial portion orthumb pad of a plunger contacts a lateral catch or trigger finger of thepassive needle guard. As the thumb pad of the plunger is moved distally,the trigger finger is forced laterally which results in a shield beingforced distally to cover a needle of the syringe or in some designs, thesyringe needle withdraws into the shield.

The present disclosure describes a needle guard device or system thatcan be used with drugs requiring reconstitution without activating thesafety mechanism, yet provides needle safety shielding after the drughas been injected into the patient. In a preferred embodiment, theneedle guard device would be assembled and sold with a syringe that ispreferably pre-filled with the diluent. In a preferred embodiment, aclip is coupled to the needle guard during the reconstitution phase. Theclip is configured to interact with the needle guard such that theshield is not activated to the extended position when the thumb pad ofthe plunger contacts the trigger fingers. Following reconstitution, theclip can be removed and the reconstituted medicine can be administeredto the patient. During administration, the shield of the needle guardcan be activated to extend and cover the needle.

DESCRIPTION OF THE DRAWINGS

FIG. 1 shows an unassembled version of an exemplary embodiment of thedevice depicting the drug vial, clip, plunger, and the needle guard withan installed syringe.

FIG. 2 shows an exemplary embodiment wherein the clip is attached to theproximal portion of the needle guard.

FIG. 3 shows an exemplary embodiment wherein the clip is attached to theproximal portion of the needle guard and the plunger is retracted fullyin the proximal direction.

FIG. 4 shows an exploded view of the proximal portion of the deviceshown in FIG. 3.

FIG. 5 shows an exemplary embodiment of the device with a reconstitutionneedle attached.

FIG. 6 shows an exemplary embodiment of the device showing the plungerin the distal position and an administration needle coupled to thedistal end of the syringe.

FIG. 7 shows a profile sectional view of the proximal portion of theneedle guard with the clip removed. The dotted outline of the shieldtrigger fingers are shown in the unlatched position. The unlatchedposition is created when the plunger advances distally to an extent thatthe curved undersurface of the thumb pad pushes against the triggerfingers and displaces them laterally such that the latch surfaces of theshield trigger fingers and body are no longer engaged and will allow theshield to move distally with respect to the body unless prevented by theclip.

FIG. 8 shows an exemplary embodiment of the device with the shield inthe extended position.

DETAILED DESCRIPTION

Turning to the figures, FIG. 1 depicts an exemplary embodiment of thepresent needle safety guard device 5 and related components in anunassembled arrangement. As will be discussed in greater detail herein,FIG. 1 shows a drug vial 200, needle guard 40 housing a syringe 10, clip90, and plunger 30. In FIG. 1, the clip 90 is shown separated from therest of the safety device to better illustrate the features of the clip90, however, in a preferred embodiment the clip 90 is connected to themain part of the safety device 5 as shown in FIG. 2.

In accordance with one aspect of the present disclosure, a medicinecartridge, such as a syringe 10 is provided (FIG. 1). Preferably, thesyringe 10 has a substantially smooth-walled cylindrical barrel 12, ahub or distal end 14 that is the administration end, and a proximal end16 having a flange 18. The cylindrical barrel 12 typically ismanufactured from substantially clear glass. Alternatively, the barrel12 may be manufactured from plastic, e.g., polypropylene, k-resin, orpolycarbonate, and the like.

The barrel 12 of the syringe 10 may be pre-filled with a diluent, or maybe filled with the diluent at a later step. Preferably the syringe 10,if pre-filled, also comprises a label or markings that indicates thequantity and type of diluent. For example, a sticker or label may beattached to the barrel 12 of the syringe 10 which provides the name ofthe diluent and the volume of the diluent. The diluent may be of anytype known in the art including, but not limited to, sterile water,saline, 5% Aqueous Dextrose or the like. Alternatively, the user mayaspirate the diluent into the syringe from a vial or container.

The proximal end 16 of the barrel 12 is configured to receive a stopper20 and a plunger 30 (FIGS. 1 and 7). The stopper 20 is configured to beslidably coupled into the cylindrical barrel 12 and movable from aproximal position to a distal position. The stopper 20 is preferablymade of pliable rubber, thermoplastic rubber, plastic or similarmaterial. The plunger 30 comprises a stem 32, a distal end 34, and aradial portion or thumb pad 36 (FIG. 1). The plunger 30 is generallymade of plastic, e.g. polypropylene, k-resin, or polycarbonate, or thelike.

The distal end 14 of the cylindrical barrel 12 preferably comprises aneedle port or Luer fitting (FIG. 1). The Luer fitting may be configuredto couple with several different sizes of needles with differentdiameters and lengths or with other components that include a Luerfitting or other type of holder. The needles and components may beconnected by a Luer connector, Luer slip, Luer, or other holder as isknown in the art. The Luer fitting can be either of the slip version (nothreads) or include threads. The Luer fitting is configured to allowinterchanging of the needle and/or components so a user may use the mostappropriate needle or component during filling the syringe,reconstitution, and administration of the medication to a patient.

A first needle or reconstitution needle 8 can be attached to the Luerfitting (FIG. 5). The reconstitution needle 8 is preferably used duringreconstitution and then replaced by a second, administration needle 15(FIGS. 6 and 8) prior to administration of the medication.

The syringe 10 is housed inside the needle guard 40 wherein the needleguard 40 is preferably a passive needle guard (FIG. 1). Safety shielddevices generally function, by covering the needle with a rigidcylindrical shield that surrounds the needle and projects far enoughbeyond the distal tip of the needle so as to prevent a user's fingerfrom coming in contact with the needle tip (FIG. 8). To prevent a userfrom forgetting to deploy the safety shield, preferred safety devicesoperate passively or automatically by providing a mechanism thatinitiates and physically executes the shielding of the needle after theinjection has been completed. The passive needle guard 40 generallycomprises a body 50 for receiving and holding the syringe 10, a shield60 slidably attached to the body 50, and a spring mechanism 55 (FIG. 8).Both the body 50 and the shield 60 are generally molded from plastic,such as, polypropylene, k-resin, or polycarbonate, or the like. In apreferred embodiment, the body 50 and the shield 60 are substantiallyclear to facilitate observation of the syringe 10 therein.Alternatively, the body 50 and the shield 60 may be translucent oropaque, and may be colored, such as a latex color, a flesh tone, or aprimary color. The body 50 may comprise opposing side rails defining twoelongate openings or windows 51 extending at least partially between aproximal end 52 and a distal end 53 of the body 50 (FIG. 8).

The shield 60 is a tubular member adapted to slidably fit on the body 50and has a proximal end 62 and a distal end 64 (FIGS. 1 and 8). In apreferred embodiment, one or more trigger fingers 66 extend proximallyfrom the proximal end 62 of the shield 60 (FIG. 7). The trigger fingers66 may include a first catch 68 that is configured to engage a secondcatch 58 on the proximal end 52 of the body 50 of the needle guard 40.Engagement between the first catch 68 and the second catch 58 retainsthe shield 60 in a first, retracted position. This latched configurationis further secured by an angled orientation of the latch surfaces, whichwhen combined with the force of the spring 55 urging these surfacesagainst each other, places a component of force on the trigger fingers66 directed toward the centerline. Preferably, the one or more triggerfingers 66 are elongate fingers having a proximal tip 67 that isengageable by the thumb pad 36 of the plunger 30 as it is depressed toaxially compress and deflect the one or more trigger fingers 66 radiallyoutwardly, as is discussed further below. In a preferred embodiment, theshield 60 further includes an anti-rotation tab 69 which extendsproximally from the proximal end 62 (FIGS. 2 and 6). The anti-rotationtab 69 interacts with the flange 18 of the syringe 10 and preventsrotation of the syringe 10. Once the needle guard 40 has been activated,the anti-rotation tab 69 is no longer in proximity to the flange 18 andthe syringe can be rotated as desired.

The passive needle guard 40 also includes a spring mechanism 55 coupledto the body 50 and the shield 60 for biasing the shield 60 towards anextended position when the trigger fingers 66 are deflected radially(FIG. 8).

The clip 90 is removably coupled with the needle guard 40. The clip 90can include a tab 95 that creates a physical barrier to removal of theplunger from the needle guard safety device 5 (FIGS. 3 and 4). When theplunger is moved proximally, the tab 95 on the clip 90 prevents a userfrom accidentally removing the plunger 30 (FIG. 3).

To prevent the relative motion of the safety shield 60 during the stepsof reconstitution, the clip 90 retains the shield in the retractedposition through the interaction of one or more extensions 94, 96disposed on the distal and proximal portions of the clip 90 thatinteract with the shield 60 and body 50 of the needle guard 40 (FIGS. 1and 4). In a preferred embodiment, the proximal extensions 94 extendaxially from the clip 90 and are removably coupled with a proximalportion of the body 50. The distal region of the clip 90 preferablyincludes one or more distal extensions 96 that are removably coupledwith the proximal end 62 of the shield 60. The interaction of theextensions 94, 96 with the shield and body prevent the movement of theshield distally with respect to the body. Therefore, even if the triggerfingers 66 are triggered during reconstitution, the shield cannottransition to the second, extended position and instead remains in theretracted position. In a most preferred embodiment, the extensions 94,96 retain the body and shield in a slightly closer position than thetrigger fingers 66 would on their own. This arrangement facilitates therelatching of the trigger fingers 66 following the reconstitutionprocess as discussed below.

In an alternative embodiment, the clip 90 can be configured to interactwith the distal end of the needle guard 40 to retain the shield 60 andbody 50 in the retracted position when the clip 90 is attached. In thisembodiment, the extensions 94, 96 of the clip 90 can be configured toengage (1) the distal end 64 of the shield 60 and (2) the body 50slightly proximal of a catch 92 disposed near the distal end 53 of thebody 50.

In a preferred embodiment, the clip 90 includes a pair of opposing ribs98 that extend laterally from the sides of the clip 90. The ribs 98 aredesigned to facilitate removal of the clip 90 following thereconstitution step as discussed further below.

The syringe 10 can be used to administer a lyophilized or concentrateddrug to a patient. The lyophilized drug or concentrated drug may be ofany type known to those of skill in the art. Preferably, the lyophilizedor concentrated drug is stored in a vial 200 or container such as aglass vial (FIG. 1). The vial 200 may include a cover such as a rubberstopper, septum, or cap that can be penetrated by a needle. In apreferred embodiment, the vial 200 is made of a substantially clearglass so that the user can ensure that the diluent and lyophilized drughave been properly and fully mixed.

Assuming that the syringe is pre-filled with a diluent, the steps ofreconstituting the drug and administering it into the patient would beto first insert the reconstitution or first needle 8 into the drug vial200. The plunger 30 is then advanced distally to expel the diluent fromthe syringe 10 into the drug vial 200.

If the syringe is not pre-filled with the diluent, the first step in theprocess would be to aspirate diluent into the syringe from a vial orother source of the desired diluent. All other steps in the processwould proceed as described above.

It is at this point that the problems with existing safety devices wouldarise, since advancing the plunger 30 to expel the diluent in the drugvial 200 would trigger the safety shield mechanism of existing safetydevices. With the shield now covering the distal end of the device, therest of the reconstitution steps would be impossible to perform and,additionally, the injection needle would not be accessible in order toinject the patient.

The clip 90 prevents the shield from transitioning to the extendedposition. Specifically, the extensions 94, 96 disposed on the distal andproximal portions of the clip 90 interact with shield 60 and body 50such that the shield is retained in the first, retracted position.

The plunger 30 can then travel the full stroke to empty the syringecontents during reconstitution. Even though the safety shield mechanismwill have been triggered (i.e. the thumb pad 36 will contact the triggerfingers 66), the shield 60 will not advance to the shielded positionbecause the interaction of the extensions 94, 96 on the clip 90 maintainthe shield in the first, retracted position. Because the trigger fingers66 have an elastic force urging them back into the latched position, thelatch mechanism is reversible if the shield 60 has not moved forward.When the plunger 30 is pulled proximally to draw the drug mixture fromthe vial 200 into the syringe 10, the trigger fingers 66 will relatchthemselves against the second catch 58 on the body 50 so that the needleguard 40 is able to trigger the next time the plunger 30 is advancedsufficiently distally (FIG. 6).

After the drug has been dissolved in the diluent, the plunger 30 iswithdrawn proximally, pulling the drug mixture into the syringe 10 (FIG.3). In a preferred embodiment, a circumferential rib 35 on the distalend 34 of the plunger 30 interferes with the tab 95 on the clip 90preventing the full withdrawal of the plunger 30, so that users will notinadvertently and surprisingly remove the stopper 20 from the syringe 10and expose the drug to a non-sterile environment (FIG. 4). Preferably,the needle 8 used for reconstitution is replaced with an injectionneedle 15 having a Luer fitting (FIG. 6). The anti-rotation tab 69 onthe proximal end of the shield prevents rotation of the syringe withinthe needle guard. Preventing rotation of the syringe facilitates removaland coupling of needles or other components to the Luer lock. The clip90 is then removed in order to administer the medication. The medicationis now ready for injection into the patient and the needle guard 40should deploy in the normal manner after the medication has beeninjected into the patient.

As discussed above, the thumb pad 36 of the plunger 30 is sized andshaped to displace the trigger fingers 66 laterally away from thelatched position that connects them to the body 50 to an unlatchedposition that substantially disconnects them from the body 50 when theplunger is advanced sufficiently far forward distally, preferably farenough forward that the contents of the syringe 10 are expelled, butbefore the plunger 30 is arrested by the stopper 20 reaching the distalend of the syringe 10 (FIGS. 7 and 8). As the medication is beinginjected into the patient, the plunger 30 will displace the triggerfingers 66 causing the force of the spring 55 to move the shield 60forward preventing the trigger fingers 66 from relatching and initiatingthe deployment of the safety shield 60. The dotted lines in FIG. 7depict the movement of the trigger fingers 66 from the latched positionto the unlatched position.

After the plunger 30 is fully advanced and the safety shield mechanismhas been released, the shield 60 is either moved distally relative tothe syringe 10 and needle 15 or the syringe 10 and needle 15 are movedproximally with respect to the shield 60. Passive or automaticdeployment of the safety shield 60 is accomplished by way of thecompression spring 55 pushing the shield 60 distally and/or the syringe10 and needle 15 proximally. The spring force is released to the shield60 and body 50 when the trigger fingers 66 are displaced from the latchconfiguration. The spring 55 is of sufficient size to move the shield 60far enough to shield the needle 15 from the user (FIG. 8). In apreferred embodiment, a locking mechanism holds the shield in theextended position. The locking mechanism may comprise, for example, aset of cooperating detents or catches 92, 93 on the shield 60 and body50 that maintain the shield in the extended position (FIG. 6).Regardless of the relative motion of the safety shield 60, what iscommon to all devices is that the safety shield 60 is actuated after theplunger has been advanced to empty the syringe contents.

Although preventing the shield from deploying or moving distally overthe syringe has been described, it is understood that the presentinvention would also apply to devices that move the syringe and needleproximally.

While the invention is susceptible to various modifications, andalternative forms, specific examples thereof have been shown in thedrawings and herein described in detail. It should be understood,however, that the invention is not to be limited to the particular formsor methods disclosed, but to the contrary, the intention is to cover allmodifications, equivalents, and alternatives falling within the spiritand scope of the appended claims.

The invention claimed is:
 1. A method of administering lyophilizeddrugs, the method comprising displacing a diluent from a syringe systeminto a medication vial comprising a medication, wherein the syringesystem includes a syringe having a cylindrical barrel configured toreceive a plunger, the syringe comprising a proximal end and a distalend, wherein the distal end is configured to receive a needle, a needleguard coupled to the syringe, the needle guard comprising a body beingconfigured to receive the syringe and a shield slidable between aretracted position and an extended position, the shield comprising oneor more trigger fingers that are releasable when a radial element of theplunger contacts the one or more trigger fingers; and a clip removablycoupled to a proximal portion of the body of the needle guard, whereinthe clip is configured with respect to the needle guard such that theinteraction of the clip and the needle guard prevents the shield fromtransitioning to the extended position when the one or more triggerfingers are contacted by the radial element; wherein the step ofdisplacing comprises moving the plunger in a distal direction such thatthe radial element of the plunger contacts the one or more triggerfingers of the needle guard and the clip prevents transitioning of theshield to the extended position; and withdrawing the therapeutic agentfrom the medication vial.
 2. The method of claim 1, further comprisingremoving the clip; and advancing the plunger distally to administer themedication.
 3. The method of claim 2, wherein the step of advancingactivates the needle guard and the shield is biased by a spring to anextended position covering a needle of the syringe.
 4. The method ofclaim 1, further comprising mixing the diluent and the medication in themedication vial to form a mixture.
 5. The method of claim 4, wherein theone or more trigger fingers return to a latched position following themixing step due to the interaction of the clip and needle guard.
 6. Themethod of claim 4, wherein the step of mixing comprises moving theplunger proximally to draw the mixture into the cylindrical barrel. 7.The method of claim 1 further comprising aspirating a diluent from adiluent vial.